• Parasites, Hosts and Diseases
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• v.59 no.4
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• pp.427-432
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• 2021

The infection status of zoonotic trematode metacercariae (ZTM) was investigated in total 568 freshwater fishes (19 species) from the irrigation canal of Togyo-jeosuji (Reservoir) in Cheorwon-gun, Gangwon-do, the Republic of Korea for 3 years (2018-2020). All fishes were examined using the artificial digestion method. The metacercariae of Clonorchis sinensis (CsMc) were detected in 180 (43.8%) out of 411 fish of positive species, and their infection intensity was 38 per fish infected (PFI). Especially, in 2 fish species, i.e., Pseudorasbora parva and Puntungia herzi, the prevalence was 82.1% and 31.3%, and the infection intensity with CsMc was 88 and 290 PFI, respectively. Metagonimus spp. metacercariae (MsMc) were found in 403 (74.1%) out of 544 fish of positive species, and their infection intensity was 62 PFI. In the pale chub, Zacco platypus, the prevalence of MsMc was 98.6%, and their infection intensity was 144 PFI. Centrocestus armatus metacercariae were detected in 171 (38.9%) out of 440 fish of positive species, and their infection intensity was 1,844 PFI. Echinostoma spp. metacercariae were found in 94 (19.6%) out of 479 fish of positive species, and their infection intensity was 3 PFI. Metorchis orientalis metacercariae were detected in 43 (29.3%) out of 147 fish of positive species, and their infection intensity was 4 PFI. By the present study, it has been confirmed that some species of ZTM, including CsMc and MsMc, are prevalent in fishes from the irrigation canal of Togyo-jeosuji in Cheorwon-gun, Gangwon-do, Korea.

• Parasites, Hosts and Diseases
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• v.59 no.3
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• pp.265-271
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• 2021

We surveyed on the infection status of zoonotic trematode metacercariae (ZTM) in freshwater fishes from Soyang-cheon (a branch stream of Mangyeong-gang) in Wanju-gun, Jeollabuk-do, the Republic of Korea. A total of 927 fishes were individually examined with the artificial digestion method during 2013-2015 (462 fish in 15 spp.) and 2018-2019 (465 fish in 25 spp.). Clonorchis sinensis metacercariae were detected in 207 (31.4%) out of 659 fishes in 14 positive fish species (PFS), and their mean intensity was 114 per fish infected (PFI). Metagonimus spp. metacercariae were found in 302 (37.4%) out of 808 fishes in 21 PFS, and their mean intensity was 12 PFI. Centrocestus armatus metacercariae were detected in 222 (59.0%) out of 376 fishes in 12 PFS, and their mean intensity was 383 PFI. Echinostoma spp. metacercariae were found in 139 (22.1%) out of 628 fishes in 10 PFS, and their mean intensity was 7 PFI. Clinostomum complanatum metacercariae were detected in 14 (6.5%) out of 214 fishes in 4 PFS, and their mean intensity was 2.4 PFI. Metorchis orientalis metacercariae were detected in 36 (13.5%) out of 267 fishes in 5 PFS, and their mean intensity was 4.3 PFI. Conclusively, the prevalence and infection intensity of ZTM is generally not so high in fishes from Soyang-cheon. However, those of C. sinensis metacercariae are more or less higher in 2 fish species, Pungtungia herzi and Sarcocheilichthys variegatus wakiyae.

• Korean Journal of Veterinary Research
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• v.52 no.2
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• pp.65-68
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• 2012

Feline parasites were investigated in the area of Suwon in Korea from September to October, 2003. Wild cat had spread to zoonotic parasites, these parasites could cause infection with a person. People have a lot of interest in parasite infection of wild cat. This article reviews rate of infection of a parasites and kind of a parasite of wild cats. We will report the critical characteristic features of parasites to a better understanding of the disease. The incidence rates of Toxocara cati, Trichuris felis, Ancylostoma braziliense and Capillaria sp were 37.0, 4.3, 1.1 and 1.1% in nematodes. Those of Taenia taeniaformis and Opisthorchis sp were 2.2 and 1.1% in cestode and trematode. Those of Isospora felis, Toxoplasma gondii, and Sarcocystis sp were 8.7, 9.8, and 2.2% in protozoa. Almost of these were zoonotic parasites without Isospora felis.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.358-367
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• 2021

The World Health Organization (WHO) has declared the coronavirus disease 2019 (COVID-19) as an international health emergency. Current diagnostic tests are based on the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method, which is the gold standard test that involves the amplification of viral RNA. However, the RT-qPCR assay has limitations in terms of sensitivity and quantification. In this study, we tested both qPCR and droplet digital PCR (ddPCR) to detect low amounts of viral RNA. The cycle threshold (CT) of the viral RNA by RT-PCR significantly varied according to the sequences of the primer and probe sets with in vitro transcript (IVT) RNA or viral RNA as templates, whereas the copy number of the viral RNA by ddPCR was effectively quantified with IVT RNA, cultured viral RNA, and RNA from clinical samples. Furthermore, the clinical samples were assayed via both methods, and the sensitivity of the ddPCR was determined to be equal to or more than that of the RT-qPCR. However, the ddPCR assay is more suitable for determining the copy number of reference materials. These findings suggest that the qPCR assay with the ddPCR defined reference materials could be used as a highly sensitive and compatible diagnostic method for viral RNA detection.

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.797-801
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• 2016

Heishui county, located in northwest Sichuan province, southwestern China, is an endemic area of zoonotic visceral leishmaniasis (VL) and is the most intractable area. VL is never destroyed in it. Asymptomatic dogs (Leishmania parasites have been diagnosed but clinically healthy) are considered to be a potential reservoir host in zoonotic VL area, and most can lead to infection of individuals, that is a new challenge for controlling VL in humans. The present study aimed to assess the Leishmania infection rate of asymptomatic dogs in Heishui county. Total 105 asymptomatic domestic dogs were gathered from 4 districts in Heishui county to investigate the infection rate with serological and molecular methods based on ELISA and kinetoplast minicircle DNA(kDNA) PCR, respectively. Out of 105 dogs, 44 (41.9%) were positive by more than 1 method; 21 (20.0%) were positive by ELISA, and 30 (28.6%) were positive by kDNA-PCR. Our study showed that Leishmania infection of domestic dogs which is clinically healthy is prevalent in the studied district, and the asymptomatic dogs infected by Leishmania may be the primary reason for the prevalence of visceral leishmaniasis in the area.

• IMMUNE NETWORK
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• v.21 no.2
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• pp.14.1-14.17
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• 2021

Scrub typhus develops after the individual is bitten by a trombiculid mite infected with Orientia tsutsugamushi. Since it has been reported that pneumonia is frequently observed in patients with scrub typhus, we investigated whether intranasal (i.n.) vaccination with the outer membrane protein of O. tsutsugamushi (OMPOT) would induce a protective immunity against O. tsutsugamushi infection. It was particular interest that when mice were infected with O. tsutsugamushi, the bacteria disseminated into the lungs, causing pneumonia. The i.n. vaccination with OMPOT induced IgG responses in serum and bronchoalveolar lavage (BAL) fluid. The anti-O. tsutsugamushi IgA Abs in BAL fluid after the vaccination showed a high correlation of the protection against O. tsutsugamushi. The vaccination induced strong Ag-specific Th1 and Th17 responses in the both spleen and lungs. In conclusion, the current study demonstrated that i.n. vaccination with OMPOT elicited protective immunity against scrub typhus in mouse with O. tsutsugamushi infection causing subsequent pneumonia.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.93-100
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• 2018

Some small mammals occur as household pests and harbour a number of parasites that could be of public health importance. This study profiled the helminth and protozoan parasites in trapped small mammals within and around human dwelling places (houses) located across 4 major towns (Auchi, Benin, Ekpoma, and Uromi) and environs in Edo state, Nigeria. Six genera (Apodemus sp., Crocidura sp., Mastomys natalensis, Mus musculus, Rattus sp., and Sorex sp.) were identified from 502 trapped small mammals. Overall, M. musculus (71.9%) and Rattus rattus (20.1%) were the most frequently trapped. In total, on examination of blood, gastrointestinal contents, and brain tissues, 12 helminth taxa (Angiostrongylus sp., Aspicularis sp., Capillaria sp., Gongylonema sp., Heterakis spumosa, Hymenolepis diminuta, Hymenolepis nana, Mastophorus muris, Moniliformis moniliformis, Nippostrongylus brasiliensis, Strongyloides sp., Trichosomoides sp., and Trichuris sp.), and 6 protozoan parasites (Babesia sp., Trypanosoma lewisi, Plasmodium sp., Eimeria sp., Isospora sp., and Toxoplasma gondii) were isolated. Most prevalent helminths with relatively heavy mean intensity were Strongyloides sp. and Heterakis spumosa, while Plasmodium, Eimeria, and Isospora were the most prevalent protozoan parasites. Generally, intrinsic factors like sex and age had marginal influence on the rate and burden of infection in M. musculus and R. rattus. Although the infection rate and prevalence of zoonotic parasites were low, they were largely recovered in rodents from Ekpoma. This study elucidates the public health implication of the presence of zoonotic parasites in these small mammals.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.119-124
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• 2015

The objective of this study was to genetically characterize isolates of Giardia duodenalis and to determine if zoonotic potential of G. duodenalis could be found in stray cats from urban and suburban environments in Guangzhou, China. Among 102 fresh fecal samples of stray cats, 30 samples were collected in Baiyun district (urban) and 72 in Conghua district (suburban). G. duodenalis specimens were examined using light microscopy, then the positive specimens were subjected to PCR amplification and subsequent sequencing at 4 loci such as glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), ${\beta}$-giardin (bg), and small subunit ribosomal RNA (18S rRNA) genes. The phylogenetic trees were constructed using obtained sequences by MEGA5.2 software. Results show that 9.8% (10/102) feline fecal samples were found to be positive by microscopy, 10% (3/30) in Baiyun district and 9.7% (7/72) in Conghua district. Among the 10 positive samples, 9 were single infection (8 isolates, assemblage A; 1 isolate, assemblage F) and 1 sample was mixed infection with assemblages A and C. Based on tpi, gdh, and bg genes, all sequences of assemblage A showed complete homology with AI except for 1 isolate (CHC83). These findings not only confirmed the occurrence of G. duodenalis in stray cats, but also showed that zoonotic assemblage A was found for the first time in stray cats living in urban and suburban environments in China.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.13-19
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• 2015

Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.

• Parasites, Hosts and Diseases
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• v.56 no.3
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• pp.281-285
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• 2018

Cryptosporidium is the most common protozoan that can infect a wide range of animals, including mammals and birds. Avian Cryptosporidium spp. can cause enteric and respiratory diseases which can be fatal in birds and some species are zoonotic. Companion birds have the potential as reservoir due to their close contact with humans. Pet shops are the major source of companion birds. However, few reports are available regarding Cryptosporidium spp. infection among companion birds kept in pet shops. The present study reports the prevalence and molecular characteristics of Cryptosporidium spp. among companion birds kept in pet shops in Japan. A total of 265 fresh fecal samples were obtained from birds kept in 4 pet shops; these birds belonged to 41 species in 3 bird orders. A nested polymerase chain reaction (PCR) assay targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. A total of 24 samples (9.1%) were positive, and Cryptosporidium spp. were detected from all pet shops. The prevalence of Cryptosporidium spp. in each of the bird orders was 6.5% (10/153) in Psittaciformes, 14.4% (13/90) in Passeriformes, and 4.5% (1/22) in Galliformes. Based on sequence analysis, 13 (54.2%) isolates were classified to C. galli, 8 (33.3%) were avian genotype III, and the remaining 3 (12.5%) were C. baileyi. No infection with zoonotic C. meleagridis and no coinfection with multiple Cryptosporidium spp. and/or genotypes were observed. The zoonotic potential of Cryptosporidium spp. infecting companion birds kept in pet shops in Japan is likely to be low.